The present invention relates to motor vehicle variable reluctance sensors.
Transmission-mounted variable reluctance sensors have been provided to sense the speed of a vehicle. Some variable reluctance sensors have electromagnetic sensing structures that include a thin wire wound around a post to create a coil. The ends of the thin wire are routed along the body of the sensing structure to a pair of terminals to which they are soldered. Typically the coil is taped or immersed in varnish so that the ends of the wire do not come loose and unwind when exposed to extreme temperatures. The extra process step to tape the ends of the coil or immerse the coil in varnish consumes time and increases costs.
Accordingly, the present invention recognizes the need for a variable reluctance sensor in which the ends of the coil are routed through the body of the sensor in such a manner that minimizes manufacturing time and costs.
A vehicle sensor includes a sensing structure that is disposed within a sensor housing. The sensing structure includes a thin wire wound around a spool to form a coil and at least two electrical leads extending from the coil. In accordance with the present invention, the spool is formed with a channel that is at least partially flanked on each side by a lip. The lips prevent the electrical leads that are disposed within the channel from slipping out of the channel between the spool and the housing and unwinding the coil.
In a preferred embodiment, the channel includes a base surface that has a partially cylindrical contour and at least two outer corners. Accordingly, the contour of the base surface urges the electrical leads into respective outer corners of the channel. Preferably, the channel includes a divider extending at least partially along the length of the channel. Also, in a preferred embodiment, the sensor includes a connector housing coupled to the sensor housing. A connector is supported by the connector housing and is electrically coupled to terminals that are, in turn, connected to the leads. Additionally, the connector housing forms a socket around the connector and the socket is sized to engage a complementarily-shaped and sized electrical connector. Preferably, the connector housing defines a first axis, the sensor housing defines a second axis, and the axes are orthogonal to each other. The sensor housing also includes an outer wall that has an abutment flange to abut a transmission housing.
In another aspect of the present invention, a vehicle sensor includes a sensor housing, a coil that is disposed within the housing, and at least two electrical leads extending from and connected to the coil. In this aspect of the present invention, the leads are disposed in a raceway that is configured for preventing the electrical leads from coming loose from the sensing structure and unwinding the coil.